Preparation and characterization of conductive chitosan/polypyrrole composites for neural repair

Abstract

Electrical stimulation showed ability to promote the proliferation and differentiation of neurons. Thus, conducting polymers such as chitosan/polypyrrole (CS/PPY) composites can be a potential material for neural repair. To improve the preparation processes and biological activity of CS/PPY composites, a novel "one step" method was proposed in the present study. Polypyrrole (PPY) nanoparticles were synthesized in chitosan (CS) solution directly. FeCl3 was used as the oxidant and dopant with a mole ratio of 4:1 to pyrrole (PY). In the Fourier Transform infrared spectroscopy (FT-IR) spectrum of CS/PPY, the two bands at 1544 cm-1 and 1040 cm-1 are characteristic PPY peaks. The scanning electron microscope (SEM) results showed that the PPY nanoparticles were distributed uniformly in CS films. When the weight ratio of PY to CS was 20%, the conductivity of the composite films was 0.51 mS/cm. The CS/PPY film adsorbed more protein than the pure CS film. The results of cell viability assay showed that the composite had good biocompatibility with PC-12 cells. The "one step" method can improve the preparation processes of CS/PPY composites and provide a promising potential material for neural tissue engineering.